Equational rules for rewriting logic

AbstractIn addition to equations and rules, we introduce equational rules that are oriented while having an equational interpretation. Correspondence between operational behavior and intended semantics is guaranteed by a property of coherence, which can be checked by examination of critical pairs and linearity conditions. We present applications of this theory to three examples where the rewrite relation is interpreted, respectively, as equality, transition and deduction

Input/Output for ELAN

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Caractérisation large bande en ligne coplanaire de couches minces ferroélectriques

National audienceNous avons présenté dans cet article une méthode de caractérisation " large-bande " de films minces ferroélectriques à partir de la mesure sous pointes d'une ligne coplanaire incorporant le film. Nous avons caractérisé un film mince de KTN de 0.5μm d'épaisseur jusqu'à 50 GHz. Nous avons quantifié les erreurs liées aux hypothèses simplificatrices de l'analyse électromagnétique rendue nécessaire par le caractère destructif de la méthode et dont le domaine de validité est limité. Enfin, la complexité de la correction des erreurs systématiques dans le cas de la caractérisation des couches minces ferroélectriques a été mise en évidenc

Intercomparison of Permittivity Measurement Techniques for Ferroelectric Thin Layers

International audienceThe dielectric properties of a KTa0.65Nb0.35O3 (KTN) ferroelectric composition for a submicronic thin layer were measured in the microwave domain using different electromagnetic characterization methods. Complementary experimental techniques (broadband methods versus resonant techniques, waveguide versus transmission line) and complementary data processing procedures (quasi-static theoretical approaches versus full-wave analysis) were selected to investigate the best way to characterize ferroelectric thin films. The measured data obtained from the cylindrical resonant cavity method, the experimental method that showed the least sources of uncertainty, were taken as reference values for comparisons with results obtained using broadband techniques. The error analysis on the methods used is discussed with regard to the respective domains of validity for each method; this enabled us to identify the best experimental approach for obtaining an accurate determination of the microwave dielectric properties of ferroelectric thin layers

Structural Insights into Viral Determinants of Nematode Mediated Grapevine fanleaf virus Transmission

Many animal and plant viruses rely on vectors for their transmission from host to host. Grapevine fanleaf virus (GFLV), a picorna-like virus from plants, is transmitted specifically by the ectoparasitic nematode Xiphinema index. The icosahedral capsid of GFLV, which consists of 60 identical coat protein subunits (CP), carries the determinants of this specificity. Here, we provide novel insight into GFLV transmission by nematodes through a comparative structural and functional analysis of two GFLV variants. We isolated a mutant GFLV strain (GFLV-TD) poorly transmissible by nematodes, and showed that the transmission defect is due to a glycine to aspartate mutation at position 297 (Gly297Asp) in the CP. We next determined the crystal structures of the wild-type GFLV strain F13 at 3.0 Å and of GFLV-TD at 2.7 Å resolution. The Gly297Asp mutation mapped to an exposed loop at the outer surface of the capsid and did not affect the conformation of the assembled capsid, nor of individual CP molecules. The loop is part of a positively charged pocket that includes a previously identified determinant of transmission. We propose that this pocket is a ligand-binding site with essential function in GFLV transmission by X. index. Our data suggest that perturbation of the electrostatic landscape of this pocket affects the interaction of the virion with specific receptors of the nematode's feeding apparatus, and thereby severely diminishes its transmission efficiency. These data provide a first structural insight into the interactions between a plant virus and a nematode vector

Rewriting Modulo a Rewrite System

We introduce rewriting with two sets of rules, the first interpreted equationally and the second not. A semantic view considers equational rules as defining an equational theory and reduction rules as defining a rewrite relation modulo this theory. An operational view considers both sets of rules as similar. We introduce sufficient properties for these two views to be equivalent (up to different notions of equivalence). The paper ends with a collection of example showing the effectiveness of this approach. ACM--CR Subject Classification: Keyword and phrases: UNIVERSIT ` A DEGLI STUDI DI PISA DIPARTIMENTO DI INFORMATICA Technical Report TR-20/95 Rewriting modulo a rewrite system Patrick Viry Abstract. We introduce rewriting with two sets of rules, the first interpreted equationally and the second not. A semantic view considers equational rules as defining an equational theory and reduction rules as defining a rewrite relation modulo this theory. An operational view considers both s..

A Rewriting Implementation of pi-calculus

. We introduce a rewriting implementation of the reduction relation of ß-calculus and prove its correctness. The implementation is based on terms with De Bruijn indices and an explicit substitution operator. The resulting rewrite rules need to be applied modulo a large and complex equational theory, and are only of theoretical interest. Applying the coherence techniques introduced in a previous paper, we transform this specification into an equivalent one that only requires rewriting modulo associativity and commutativity. This latter rewrite system can then be straightforwardly encoded in currently available rewriting-based programming languages. Finally, we sketch a possible application of this implementation as the basis for adding input-output capabilities to such languages. 1 Introduction Rewriting interpreters are very nice toys for the theoretically minded. You can feed them equations and rules, and they will show you the possible derivations, or compute normal forms, many vari..

Elimination of Conditions

We present a transformation from any conditional rewrite systems into non conditional ones and prove its correctness. The transformed systems are quite intuitive and well suited for parallel execution. We also show how termination and confluence of the original system are preserved in the transformed one

La reecriture concurrente

SIGLEAvailable from INIST (FR), Document Supply Service, under shelf-number : T 84147 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

A Rewriting Implementation of pi-calculus

We introduce a rewriting implementation of the reduction relation of $\pi$-calculus and prove its correctness. The implementation is based on terms with De Bruijn indices and an explicit substitution operator. The resulting rewrite rules need to be applied modulo a large and complex equational theory, and are only of theoretical interest. Applying the coherence techniques introduced in a previous paper, we transform this specification into an equivalent one that only requires rewriting modulo associativity and commutativity. This latter rewrite system can then be straightforwardly encoded in currently available rewriting-based programming languages. Finally, we sketch a possible application of this implementation as the basis for adding input-output capabilities to such languages